Protein synthesis is a fundamental requirement for the development of an organism and a prime target for antibiotic action. There are five separate and essential protein synthesis systems that function at different points during the development of Plasmodium species making the control of protein synthesis fundamentally different in the parasite from its human host. The expression of distinct rRNAs suggest that changing the central catalytic component of the ribosome, the rRNA, is a trigger for development. We are presently investigating both transcriptional control of the distinct rRNA genes and putative functional differences between the rRNAs, as these would be targets for intervention in the life cycle of the parasite through drug interaction. Core differences among the genes concentrate in the site for stimulation of GTP hydrolysis in a manner that may be predicted to modulate its catalytic activity. Hydrolysis of GTP is a key regulatory step in other systems and, therefore, we predict that alteration of the site may trigger the development of the parasite. The effect of changes in the GTPase site are currently being investigated in vivo by gene replacement and selective drug targeting of genes, and in vitro by transcription of synthetic genes with T7 RNA polymerase